Before you buy prescription drugs online, you should heed warning signs. One red flag is if the prices are too good to be true. Another red flag is the Canadian flag.

The U.S. Food and Drug Administration says nearly 25 percent of Internet users have ordered a prescription drug online. Though many purchases are from reputable, licensed, U.S.-based pharmacies, some are not. People who do an online search looking for a pharmacy could easily find themselves on the website of a rogue seller outside the United States. The National Association of Boards of Pharmacy notes that fewer than 3 percent of online pharmacies have the proper licensing to sell prescription medicines in the United States.

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The FDA has just begun BeSafeRx (www.fda.gov/besaferx), a campaign to educate consumers about online pharmacies. If you want to order online, the best way to ensure you're getting FDA-approved drugs from a reputable company is to use websites of U.S.-based brick-and-mortar pharmacies, FDA spokeswoman Sarah Clark-Lynn says. The major drug chains, such as Walgreen's and CVS, have trustworthy online pharmacies, as do some mass merchandisers such as Walmart. While there are several Internet-only pharmacies that are legitimate U.S.-based companies selling FDA-approved drugs online, not all can ship drugs to New York because of state licensing laws.

As for Canada, there are two potential problems, Clark-Lynn says. First, drugs sold at even legitimate Canadian pharmacies do not need FDA approval. While the medicines have been approved by Canadian authorities for sale in Canada and may have the same name and be from the same drugmaker as the one your doctor prescribed, the formulations may be different. And the real bottom line: The FDA considers importing prescription drugs from Canada to be illegal.

Second, and more dangerous, some websites you'll find doing a search for "Canadian pharmacies" are fraudulent, even though they lure you with a Canadian flag icon. "You think you're getting a prescription from our friendly neighbors to the north, and it's really a website from halfway around the world," Clark-Lynn says. These sites typically advertise drugs at a huge discount, but chances are you'll get nothing except a charge on your credit card. If you do get drugs, they may be counterfeit. "Sometimes these drugs don't contain an active ingredient or contain the wrong active ingredient," Clark-Lynn says.

For a list of online pharmacies accredited by the National Association of Boards of Pharmacy, go to

bit.ly/onlinepharmacies.